Spotlights/headlights that use Laser Activated Remote Phosphor (LARP) technology are known. In the case of this technology, a conversion element (converter, wavelength conversion element, phosphor arrangement, phosphor element) arranged at a distance from a radiation source and including or consisting of a phosphor is irradiated with an excitation radiation, in particular an excitation beam or pump beam or pump laser beam, in particular with the excitation beam of a laser diode. The excitation radiation is at least partly absorbed by the phosphor and at least partly converted into a conversion radiation or into a conversion light, the wavelengths and hence spectral properties and/or color of which are/is determined by the conversion properties of the phosphor. In the case of down-conversion, the excitation radiation of the radiation source is converted by the irradiated phosphor into conversion radiation having longer wavelengths than the excitation radiation. By way of example, blue excitation radiation, in particular blue laser light, can thus be converted into red and/or green and/or yellow conversion radiation with the aid of the conversion element. In the case of a partial conversion, by way of example, a superimposition of non-converted blue excitation light and yellow conversion light produces white useful light.
A spotlight/headlight having LARP technology includes for example a lighting device having a housing. The laser diode can then be arranged in said housing. A substrate including a phosphor that can be irradiated by the excitation radiation can then be provided between the laser diode and a housing opening. In order to detect cracking at the phosphor, a fracture detector is arranged. Such a fracture detector is disclosed for example in DE 10 2015 213 460. It has an electrically conductive line track arranged on the phosphor. In this case, the line track is connected to an electronic evaluation unit, which can be used to detect in particular a change in resistance at the line track on account of a crack in the phosphor. The temperature-dictated change in the resistance value is concomitantly taken into account here.